Alcohol addiction located in the “stop” and “go” centres of the brain: study

Scientists investigating the neurological bases contributing to alcoholism and other addictive behaviours have found two type of brain cells that when activated, either tell the person to keep on drinking or to stop. Using mice that were habituated to regularly consume alcohol, researchers at Texas A&M’s College of Medicine found that after repeated cycles of alcohol intake and alcohol withdrawal,specific neural pathways in the striatum region of the mouse brain – responsible for stimulus-response learning and reward-reinforcement behaviour – were strengthened while the signal along other pathways became less powerful. The research team found that these “go” and “no go” neural pathways, called D1 and D2 dopamine receptors, effectively create the neurological framework for addiction. “These results provide insight into the synaptic and cell type-specific mechanisms underlying alcohol addiction,” say the study’s authors, whose work is published in the journal Biological Psychiatry, “and they identify targets for the development of new therapeutic approaches to alcohol abuse.” The health impacts of alcohol use and abuse are well known. Long term alcohol dependence increases the risk of liver, breast and digestive track cancers, among others, diabetes, cirrhosis and pancreatitis. The Canadian Centre on Substance Abuse states that in 2014, 886,000 Canadians aged 15 and older -an estimated 3.2 per cent of the population -were dependent on alcohol or abused alcohol, with a 2002 study estimating the total cost of alcohol-related harm to Canadians at $14.6 billion annually. A report by the Centre for Addiction and Mental Health (CAMH) ranks Canada’s provinces in terms of their success at creating effective harm-reduction policies related to alcohol consumption, including pricing regulations and legal drinking age standards, alcohol availability, marketing and warning labels. While the report gave Ontario the highest aggregative marks and Quebec the lowest, lead author Norman Giesbrecht says all the provinces need to step up in terms of alcohol-related policies. “There’s lots of room for improvement,” says Giesbrecht, senior scientist at CAMH. “Alcohol does not get a lot of attention in regards to prevention. We have to give it more attention if we want to reduce the harm.” A new study from the University of California, San Francisco, finds that laws restricting alcohol sales have a significant effect on alcohol consumption rates yet their impact on cardiovascular health is less clear, a result which matches previous findings which show that alcohol consumption may be a risk factor for some forms of cardiovascular disease while potentially lowering the risk for others. Researchers looked at various counties within the state of Texas, some of which were identified as “dry” (where alcohol sales are completely restricted), others as “wet” and still others as having experienced a recent changeover from dry to wet. The team found that in comparison to the dry counties, the prevalence of liver disease and artrial fibrillation (irregular heartbeat) was higher among hospitalized residents of both wet and “dry to wet” counties but that there was a lower prevalence and incidence of heart attacks and congestive heart failure in the wet counties, with the study’s authors saying that these results, “have health implications relevant to people with and at risk for various types of cardiovascular disease.”

About Jayson MacLean

Jayson is a writer, researcher and educator with a PhD in political philosophy from the University of Ottawa. His interests range from bioethics and innovations in the health sciences to governance, social justice and the history of ideas.